Engine torque measurement is an important parameter used in the development of modern vehicle powertrains. In particular, much transmission development is conducted in test vehicles as opposed to on dynamometers. For this reason, it is advantageous to measure the torque output from an engine without requiring changes to the powertrain which may not easily be accommodated within an actual vehicle. A number of experimental means have been developed to measure engine output torque, such as modifying the flex plate or flywheel coupling that connects the engine to the transmission. Current methods are expensive and require significant design effort to isolate the torsional forces and fit the requisite components into the existing space constraints. Flex plate and flywheel solutions must also contend with high g-forces, vibration, and high temperatures.
Another solution employed is to rely on the calculated engine output torque data available from an engine controller. The torque signal or algorithm from the engine controller is a function of the throttle position, engine revolutions-per-minute (RPM), ignition advance, fuel flow, and a several other measurements. The torque algorithm is developed from dynamometer and vehicle testing where the actual torque is measured using torque sensors. These initial measurements are not always available or finalized at the early stages of engine and transmission development.
What is needed is a system and method for measuring engine torque during the development process without the need to modify the flex plate or flywheel and which do not rely on algorithmic calculations.